Estimating Satellite Orbital Drag During Historical Magnetic Superstorms. Issue 11 (5th November 2020)

• Record Type: Journal Article
• Authors: Oliveira, Denny M.; Zesta, Eftyhia; Hayakawa, Hisashi; Bhaskar, Ankush
• Is Part Of: Space weather. Volume 18:Issue 11(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-11-05
• Subjects: historical data -- magnetic superstorms -- thermosphere density -- satellite orbital drag; Space environment -- Periodicals; 551.509992
• DOI: 10.1029/2020SW002472
• Languages: English
• ISSNs: 1542-7390

Abstract

Abstract: Understanding extreme space weather events is of paramount importance in efforts to protect technological systems in space and on the ground. Particularly in the thermosphere, the subsequent extreme magnetic storms can pose serious threats to low Earth orbit (LEO) spacecraft by intensifying errors in orbit predictions. Extreme magnetic storms (minimum Dst ≤ −250 nT) are extremely rare: Only seven events occurred during the era of spacecraft with high‐level accelerometers such as CHAMP (CHAllenge Minisatellite Payload) and GRACE (Gravity Recovery And Climate experiment) and none with minimum Dst ≤ −500 nT, here termed magnetic superstorms. Therefore, current knowledge of thermospheric mass density response to superstorms is very limited. Thus, in order to advance this knowledge, four known magnetic superstorms in history, that is, events occurring before CHAMP's and GRACE's commission times, with complete data sets, are used to empirically estimate density enhancements and subsequent orbital drag. The November 2003 magnetic storm (minimum Dst = −422 nT), the most extreme event observed by both satellites, is used as the benchmark event. Results show that, as expected, orbital degradation is more severe for the most intense storms. Additionally, results clearly point out that the time duration of the storm is strongly associated with storm time orbital drag effects, being as important as or even more important than storm intensity itself. The most extreme storm time decays during CHAMP/GRACE‐like sample satellite orbits estimated for the March 1989 magnetic superstorm show that long‐lasting superstorms can have highly detrimental consequences for the orbital dynamics of satellites in LEO. Plain Language Summary: We investigate drag effects on satellites orbiting Earth in its upper atmosphere during magnetic storms caused by the impacts of solar superstorms. During magnetic storms, the upper atmosphere is heated and expands upward, resulting in increased drag forces on satellites flying in those regions. Enhanced drag effects directly impact operations of such spacecraft, for instance, orbital tracking and predictions, maneuvers, and lifetime maintenance. The U.S. Federal Government has recognized space weather phenomena as natural hazards, and the understanding of their consequences, particularly during extreme circumstances, is of paramount importance. The very extreme events, here termed magnetic superstorms, occurred before the space era when no in situ observations of the atmospheric density are available. Therefore, we use an empirical model to estimate drag from these historical events. Results generally show that the most extreme events drive the most severe effects. Additionally, we point out that another storm feature, its time duration, can play a significant role in enhancing drag. Therefore, we argue that space weather forecasters should be aware of events with long duration, particularly the ones caused by sequential impacts of solar disturbances on the Earth's magnetic field, when predicting and forecasting the subsequent drag effects on satellites in the upper atmosphere. Key Points: Satellite orbital drag during magnetic superstorms (standard/equivalent Dst < −500 nT) has been quantitatively estimated The November 2003 extreme magnetic storm is used as the benchmark event and for model performance assessment when predicting drag effects Interplay between storm time duration and minimum Dst and Dst‐like values determine the severity of satellite drag effects in low Earth orbit